This invention relates to a dust separator/collector arrangement of the cyclonic type, for a vacuum cleaner (suction cleaner).
Separators of the so-called “cyclonic” type are now well established in the field of vacuum cleaners for separating dust, dirt, and other matter (all herein referred to as “dust”) from the suction airflow drawn by a cleaner from whatever is being cleaned. Cyclonic separators avoid or reduce the problem of clogging of filters which, before the adoption of cyclonic separators, were used for dust separation. Very often a bag, either disposable or reusable, was used as the main separation filter for vacuum cleaners in which dust separated by the flow of air through the material of the bag was retained for later disposal.
The present invention relates more particularly to a cyclonic separator/collector assembly which utilises a first cyclonic separator for effecting a first stage of dust separation from the suction airflow of the cleaner, followed by a further cyclonic separator comprising one or more further cyclones, for further such separation. In known such separator/collector assemblies, the first cyclone is usually of a larger size than the further cyclone(s), so that it separates larger and heavier dust particles from the airflow, along with any small objects which might intentionally or otherwise be ingested by the cleaner, while the or each further cyclone is of smaller size so that air circulates at a higher speed therein and lighter and finer dust particles are separated. Some cleaners incorporate a number of further cyclones of small size connected in parallel with one another, giving the possibility of extremely efficient dust separation, although even in these cleaners it is usual to provide a filter or filters after the cyclonic separator/collector assembly.
Because the suction airflow of the cleaner has to pass through a first cyclone and one or more further cyclones in sequence, the dust separated by each cyclonic cleaning stage has to accumulate in separate receptacles, or separate parts of a common receptacle, to be retained until emptying of the receptacle(s). Generally, arrangements have been adopted in which the dust from the different cyclonic stages is emptied together. This has usually been effected either by removal of a single dust receptacle from the separator assembly and inverting the receptacle to empty collected dust therefrom, or by opening a door at the bottom of a dust receptacle part of the separator assembly, to enable accumulated dust to fall from the receptacle. In either case, the receptacle has different collection areas in which the dust separated by the different cyclonic separator stages accumulates.
Such “one step” emptying is convenient, but not always desirable. Frequently, a vacuum cleaner sucks up small items such as toys or parts thereof, or jewelry such as earrings, which are not to be thrown away. Therefore, it is necessary to empty the accumulated dust and search through it for the required article(s). Even though such an article can be expected to have been separated by the first cyclonic separating stage, it will be emptied with all the separated dust including very fine particles separated by the further separating stage. Such fine particles are unpleasant to handle and readily form an airborne dust cloud.